Field of the Invention
The present invention relates to information handling systems and more particularly to auxiliary power shutdown and power up for a server type information handling system.
Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems are powered via power supplies. Often, especially in server type information handling systems, multiple power supplies are used to provide power redundancy.
It is often desirable in the field and in development to perform an alternating current (AC) cycle an information handling system platform. By AC cycling, an information handling system removes both main and auxiliary power from the perspective of electronics downstream of the power supply for a set period of time and then restores the auxiliary power which in turn resumes the appropriate main power state. Auxiliary power usually powers logic such as a blade management controller (BMC), a remote access controller (RAC), a complex programmable logic device (CPLD), as well as various sensors and microcontrollers throughout the server type information handling system. Whereas main power is for the host processors, memory, I/O type chipsets, hard drives, etc.
One example of where an AC cycle is desirable is when updates are provided to a system CPLD. In this situation, whereas the CPLD can be remotely updated, it is often necessary for an administrator to physically perform an AC cycle on each server type information handling system via removing and reattaching the power cables. In server type information handling systems, on the fly reprogramming of CPLDs and resuming a last state is a complex sequence to accomplish reliably and in some cases is not even possible. Also, it is important when main and auxiliary power are present to maintain the state of all outputs. Maintaining the state may be accomplished by locking the output pin states or continually executing the preprogrammed logic until the newly updated logic takes effect. This process often required an AC cycle of the information handling system.
Also, during development and test of server type information handling systems, AC cycle testing can be a stressful test that is accomplished via external (and often expensive) boxes that intercept and control the AC power as well as clients with host communication for confirmation of a good boot.
Cycling AC may also provide a recovery mechanism for server management failure whenever one of the state machines enters an unknown state. For example, state machines within the remote access controller, field programmable gat arrays (FPGAs) or CPLDs may be reset into a known state by performing an AC cycle.
Also, in certain server systems, the auxiliary power is becoming larger and larger. For example, in certain server type information handling systems, a system may draw up to 100 Watts of power under a virtual standby and greater then 30 Watts under auxiliary power.